Digital design comprises the modeling of a circuit using binary elements, and the conversion of the model to physical elements. Techniques for efficient digital design are described, for example, by Synopsis Inc., in “Design Compiler® User Guide Version D-2010.03-SP2,” June, 2010.
One of the techniques used in digital design is digital pipeline, described, for example, by Ramamoorty and Li, in “Pipeline Architecture,” Journal ACM Computing Surveys (CSUR), Surveys Homepage archive, Volume 9, Issue 1, March, 1977, Pages 61-102.